PROJECT SUMMARY/ABSTRACT Significance: The Knee Biofeedback Rehabilitation Interface for Game-based Home Therapy (?KneeBRIGHT?) system combines electromyography (EMG) biofeedback with video game therapy (VGT) to provide knee osteoarthritis (OA) patients with an engaging, effective tool for conducting rehabilitation exercises at home. KneeBRIGHT aims to motivate patients with knee OA to conduct regular muscle strengthening exercise through an engaging, EMG-driven video game therapy. The system combines wireless EMG electrodes that are convenient for patients to use in a home setting with software that provides automated guidance through evidence-based, progressive exercise routines. Importantly, these exercises are presented to the patient in the form of fun and engaging games to promote a positive experience and encourage continued adherence. Problem to be Addressed: OA is the leading cause of disability in the United States. Rehabilitation through quadriceps strengthening is a well-established treatment for patients with OA of the knee, but patient adherence to exercise routines is low due to lack of guidance regarding optimal protocols and lack of engagement during the repetitive routines that patients find tedious and boring. Long-Term Goal: Improve knee OA outcomes through effective and motivating rehabilitation exercises. Phase I Results: During the Phase I effort, a prototype KneeBRIGHT system was developed and verified in a laboratory setting. The feasibility testing with 19 knee OA patients demonstrated statistically significant increases in muscle activation, engagement levels, and duration of voluntary exercise during the KneeBRIGHT exercises when compared with exercises conducted with a conventional EMG biofeedback system. Phase II Hypotheses: The Phase II program will test the hypotheses that patients performing exercise routines using KneeBRIGHT will: (1) achieve superior muscle strength gain compared to a conventional EMG biofeedback protocol; and (2) exhibit increased adherence compared to the conventional system. Phase II Summary: Barron Associates (award-winning innovators in video game therapy) has partnered with the University of Virginia for this SBIR Phase II program to demonstrate efficacy and user acceptance of the KneeBRIGHT system. The specific objectives of the Phase II program are to: (1) develop the Phase II commercial KneeBRIGHT EMG modules; (2) develop the Phase II commercial KneeBRIGHT game software with adaptive exercise protocols and expanded game activities; (3) develop a provider dashboard to enable clinicians to monitor patient performance remotely; and (4) perform efficacy testing of muscle strength, functional improvement (via Knee Osteoarthritis Outcome Score), and adherence (when compared to a conventional system) with knee OA patients in a 12-week clinical trial. Impact: The system will have a significant overall impact on public health by increasing patient adherence to home exercise and thereby reducing pain symptoms and restoring physical function to knee OA patients.